Minor PHP permissions fix - C

I am having permissions issues with the checkout process on my website. This had worked fine for years but now due to some server changes it is no longer working. Below is a description of the problem from my hosting company:

The issue is documented in /home/lenstool/public_html/secure/error_log:

[12-Dec-2014 17:41:44 America/New_York] PHP Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0

Essentially, when the signup process starts, a session file is created by 'mortgage', since the session originally starts on [url removed, login to view] This creates a session file in /tmp/ like this:

However, the signup is then redirected to a completely different site on a different account: [url removed, login to view] 'lenstool'

The 'lenstool' account does not have access to these session files. This may have been working before on DSO because DSO would have created these files with user 'nobody'. However, this setup is typically considered very insecure, since it can potentially result in 2 different accounts being compromised. Your developers need to code this transition in such a way that they can be contained within the same account, ie 'mortgage'.

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